The present invention relates to a process and apparatus for the recovery of energy from an ozone production unit.
More particularly, the present invention relates to such a process and apparatus whereby the recovered energy may be employed for purposes of heating, air-conditioning, preparing sanitary or industrial hot water, or particularly in accordance with an advantageous arrangement for destroying catalytically or thermally residual ozone remaining after the ozone has been used as an oxidation agent in a water treatment facility whereby water is treated by ozone produced in the ozone production unit. For example, in water treatment facilities in which ozone is used as a disinfectant, the water-ozone contact reactors are not entirely 100% efficient. Thus, it is necessary, as is known, to destroy the residual ozone either catalytically or thermally.
In conventional ozone production units that produce ozone by applying an alternating current of 10-20 kV to a high voltage electrode, thus forming a discharge between such electrode and a second, grounded metal electrode, it is known that only a small fraction, for example 5-10%, of the discharge energy is used to form ozone from the supply of gas, which generally is pressurized air or oxygen. The remainder of the electrical energy applied is converted into lost heat. The ozone yield is reduced if this heat is not effectively eliminated. Commonly, this energy is transferred to a cooling liquid, for example refrigerated water or a mixture of water and glycol.
Pretreating of the air supplied to the ozone generator by means of superpressurizing, conditioning and drying to a dew-point of -70.degree. C. also entails a large release of heat. This released heat generally is lost, with the cooling water simply being transferred toward a drain or a recycling circuit.